Update MANIFEST.in

[epierce]

Description

Add LONG_DESCRIPTION.md to the distribution to fix builds from PyPi

Related Issue

#395

Motivation and Context

LONG_DESCRIPTION.md wasn't included in the package manifest, so building the code from the PyPI package fails.

How Has This Been Tested?

Successfully built using the zipped package on my local machine

Types of changes

• [X ] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ X] My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• [X ] I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• [X ] All new and existing tests passed.